%%%-------------------------------------------------------------------
%%% @author wukai
%%% @copyright (C) 2017, <COMPANY>
%%% @doc
%%%
%%% @end
%%% Created : 01. 十二月 2017 15:20
%%%-------------------------------------------------------------------
-module(web_handler).
-author("wukai").
%% API
-export([init/2]).

init(Req0, Opts) ->
  Method = cowboy_req:method(Req0),
  #{echo := Echo} = cowboy_req:match_qs([{echo, [], undefined}], Req0),
  Req = echo(Method, Echo, Req0),
  {ok, Req, Opts}.

echo(<<"GET">>, undefined, Req) ->
  cowboy_req:reply(400, #{}, <<"Missing echo parameter.">>, Req);
echo(<<"GET">>, Echo, Req) ->
  cowboy_req:reply(200, #{
    <<"content-type">> => <<"text/plain; charset=utf-8">>
  }, Echo, Req);
echo(_, _, Req) ->
  cowboy_req:reply(405, Req).